.overlay {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
}

.position-center {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}

[data-overlay] {
  position: relative;
  z-index: 2;
  [class^="col-"],
  [class*="col-"] {
    z-index: 1;
  }
}

[data-overlay]:before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
}


@each $overlaycolorMap, $value in $overlaycolorMap {
  [data-overlay="#{$overlaycolorMap}"]:before {
    background-color: #{$value};
  }
}


@for $i from 1 through 10 {
  [data-opacity="#{1 * $i}"]:before {
    opacity: #{$i*0.1};
  }
}